Chemical Properties

Heat-Resistant Properties

Molybdenum is an important alloying agent which contributes to the hardenability and toughness of quenched and tempered steels. It also improves the strength of steel at high temperatures. It is used in certain heat-resistant and corrosion-resistant nickel-based alloys. Ferro-molybdenum is used to add hardness and toughness to gun barrels, boilers plates, tools, and armor plate. Almost all ultra-high strength steels contain 0.25% to 8% molybdenum. Molybdenum is used in nuclear energy applications and for missile and aircraft parts. Molybdenum oxidizes at elevated temperatures. Some molybdenum compounds are used to color pottery and fabrics. Molybdenum is used to make filament supports in incandescent lamps and as filaments in other electrical devices. The metal has found application as electrodes for electrically-heated glass furnaces. Molybdenum is valuable as a catalyst in there fining of petroleum. The metal is an essential trace element in plant nutrition. Molybdenum sulfide is used as a lubricant, particularly at high temperatures where oils would decompose. Molybdenum forms salts with valencies of 3, 4, or 6, but the hexavalent salts are the most stable.

Element Classification

Transition Metal

Density (g/cc) 10.22
Melting Point (K) 2890
Boiling Point (K) 4885
Appearance silvery white, hard metal
Atomic Radius (pm) 139
Atomic Volume (cc/mol) 9.4
Covalent Radius (pm) 130
Ionic Radius 62 (+6e) 70 (+4e)
Specific Heat (@20°C J/g mol) 0.251
Fusion Heat (kJ/mol)  28
Evaporation Heat (kJ/mol) ~590
Debye Temperature (K) 380.00
Pauling Negativity Number 2.16
First Ionizing Energy (kJ/mol) 684.8
Electron Configuration [Kr] 5s1 4d5
Oxidation States 6, 5, 4, 3, 2, 0
Lattice Structure Body-Centered Cubic
Lattice Constant (Å) 3.150